1. Field of the Invention
This invention relates to a remote control system for remotely controlling the audio volume on electronic equipment having an audio output and particularly on electronic home entertainment equipment possessing an earphone connection. More particularly, this invention relates to a structure for remotely controlling any piece of home entertainment equipment which possesses a plug-in receptable for an earphone by utilizing the earphone connector of said equipment in such a manner as to require no internal connection or wire connections between the remote control transmitter and the equipment to be controlled.
2. Description of the Prior Art
Many pieces of home entertainment equipment, such as television receivers, incorporate as an integral, non-removable part thereof a remote control system for allowing a user to control the volume and other functions of said equipment from a remote location. Such a remote control cannot be removed for installation in another piece of equipment and adds a substantial amount to the cost of the equipment. The consumer must bear the expense of this option at the time of purchase of said equipment.
There are also presently available remote control systems which can be retrofitted to entertainment equipment; however, those of these systems known to this inventor require internal connections to the equipment to be remotely controlled or wire connections between the hand-held controller and the equipment. Their use may void the warranty of the controlled equipment.
Calman in U.S. Pat. No. 4,027,249 issued May 31, 1977 on an invention entitled "Vehicle Radio Control Unit" discloses a self-contained control unit for use in an automobile or other vehicle containing a citizen's band radio receiver and an additional audio entertainment appliance such as an AM radio, FM radio, AM/FM radio or audio magnetic tape player. The control unit includes an external speaker for the CP receiver, a plug for insertion in a jack on the CB receiver to connect the external speaker to it, a relay for controlling the operation of the additional audio entertainment applicance and a transistor amplifier and switching circuit connected between the plug and the relay to disable the additional audio entertainment appliance whenever the CB receiver is broadcasting incoming CB signals through the external speaker. This structure essentially comprises an audio operated switch means which disconnects the audio entertainment appliance within an automobile upon the receipt of CB signals and delays the turning on of the audio entertainment appliance following the cessation for a selected time of the incoming audio signals. This structure however is of specialized application and is not suitable for use with television sets or similar equipment.
U.S. Pat. No. 4,305,155 issued Dec. 8, 1981 on an application of Romeo entitled "Exterior Mounted Remote Control Television Channel Selector" discloses a mechanical adapter for insertion over the channel selector knob on a television set to mechanically change the station received by the television set in response to signals transmitted from a hand held control unit. Again, this structure neither turns on or off the television set nor controls the audio volume of the set.
Popular Electronics, February 1981, pages 44 through 50 in an article entitled "Wireless Ad Zap Turns Off TV Commercials" discloses a hand held transmitter for sending a signal to a receiver mounted internally to the television set for enabling the viewer to turn off the sound associated with TV commercials. This particular structure requires internal modifications to the circuitry of the television set and therefore requies access to the interior wiring of the television set thereby possibly voiding its warranty.
Other patents describing certain remote control systems include U.S. Pat. No. 4,112,615 entitled "Remote Control System for a Movable Toy Vehicle", U.S. Pat. No. 4,107,613 entitled "Wireless Microphone with FM Receiver Muting System Responsive to Excessive Undesired AM Level or Low AGC Control Level", U.S. Pat. No. 3,868,639 entitled "Remote Control Receiver Responsive to Sound", U.S. Pat. No. 3,794,985 entitled "Remote Control of a Receiver", U.S. Pat. No. 4,041,400 entitled "Television Remote Control System".
Thus, there exists a need for an improved system and method for the remote control of electronic equipment having an audio output.